Lubricant and method of making the same



Patented Jan. 24, 1939 UNITED STATES PATENT OFFICE LUBRICANT AND METHOD OF MAKING THE SAliIE aware No Drawing. Application April 10, 1937,

Serial No. 136,128

Claims.

This invention relates to lubricants and methods of making the same, one of the objects being to produce a new lubricant having a number of outstanding advantages not found in the ordinary 5 mineral lubricating oils. Prior to this invention, mineral lubricating oils have been subjected to various difierent kinds of refining operations for the purpose of decreasing deterioration of the oil, stabilizing color, improving the viscosity index, increasing oiliness, and increasing the resistance to sludging. An object of the present invention is to obtain, or augment, each of these properties by merely adding to the oil a material that remains with the oil, so as to cooperate l6 therewith while the oil is in storage and also when it is in service.

The invention may-be employed as a supplement to the usual refining operations, thereby producing a new lubricant quite superior in several respects to the usual refined oils; or the degree of refining may be reduced, as the present invention provides certain conditions obtained by such refining operations, in addition to qualities not obtainable therefrom.

The material employed to accomplish all of these results includes an oily extract derived from acorns, the fruit of oak trees- This extract is soluble in petroleum and other mineral oils. It can be obtained from the acorns in any desired 30 manner.

The acorns may be crushed, dried, and macerated with the petroleum oil, and the insoluble matter separatedby filtering or any other suitable. method. Other solvents may be used for extracting the oily liquid from the acorns and the solvent removed by distillation, or the solvent together with the extract may be added directly to the petroleum product, and the solvent may be subsequently distilled from the solution. Or, the solvent and extract may remain inthe petroleum product. The extract may also I be separated from the acorns by expression or by a combination of both expression and extraction methods. In other words, the invention is not based upon, nor limited to, details of any method by which this petroleum-soluble extract is separated from the acorns or added to the petroleum product. It will also be understood that our invention is not limited to any particular oil to which the acorn extract may be added, except as specifically pointed out in the claims.

The crude acorn extract may be used with or without any refining to improve its qualities, and it may be refined separately or in conjunction with the petroleum lubricating oil. However, the

desired substances appear in the juice, or oil, just as it is expressed or extracted from the acorns. I

When this acorn oil is added to mineral oil, it results in a blend having a relatively high vis- 5 cosity index. For example, the addition of 7% acorn oil to an S. A. E. 20 motor oil increased the viscosity index from 81.5 to 96.4.

This specific example merely illustrates a function of the acorn oil which may be employed in 10 larger quantities to obtain a viscosity index considerably above 100 without in any way impairing the mineral oil. In fact, any quantity of the acorn oil will increase theviscosity index and otherwise improve the lubricating oil, and since the degree of increase in the viscosity index depends upon the quantity of acorn oil added to the mineral oil, it will be understood that the invention is not limited to the percentages herein suggested.

The following examples will illustrate the stabilizing action of acorn oil on mineral oil toward Neutral oil 219 viscosity at 100 F.

Control 154.7 mg. sludge from 10 gm. oil Control plus 7% acorn oil 87.8 mg. sludge from 10 gm. oil

Neutral oil 600 viscosity at 100 F.

Control 32.4 mg. sludge from 10 gm. oil Control plus 5% acorn oil 5.8 mg. sludge from 10 gm. oil

Obviously, the new lubricant is well adapted 45 for use in internal combustion engines, and owing to its unusual oiliness, stability, resistance to sludging and high viscosity index, the new composition herein disclosed affords a solution to the problems involved in lubricating aircraft engines.

In the past, castor oil has been widely used as a lubricant for aircraft engines because of its oiliness and high viscosity index or good viscosity-temperature relationship. Castor oil was discontinued for this type of lubrication because oi its tendency to form gummy substances. We have found that a blend of the acorn oil and mineral oil not only has the good qualities of castor oil as a lubricant, but does not form gummy substances.

The resistance to sludging as well as the cosity index, oiliness, etc., depend partly upon the constituents of the mineral oil and partly upon the percentage of acorn oil in the blend. This percentage can be increased as desired to obtain the highest efilciency and durability, or' a very small percentage may be employed, depending upon the qualities of the original mineral oil and the properties desired in the ultimate product.

We claim:

1. A lubricant comprising a mineral lubricating oil and acorn oil.

of the composition.

2.' In a lubricating oil having a high viscosity index and a high resistance to sludging, a blend comprising mineral lubricating oil and acorn oil.'

3. In the art of making lubricating oils, the method which comprises blending mineral lubrieating oil with acorn oil.

4. In the art of making petroleum lubricating oils, the method which comprises adding to petroleum oil a substantial quantity of acorn oil suilicient to materially increase the viscosity index and at the'same time materially increase the resistance to sludging.

5. A lubricating oil composition comprising a blend of mineral lubricating oil and acorn oil, the quantity of said acorn oil being at least 5% ROBERT W. PROVIN'E. HARRY T. BENNETT. 

